Richardson, 25, was a second-round pick by Seattle in 2014 (45th overall). He's caught 95 passes for 1,302 and eight touchdowns in four NFL seasons. He's also coming off a career year, hauling in 44 balls for 703 yards and six touchdowns over 16 games -- and 13 starts -- in 2017

Richardson is set to earn $20 million in guaranteed money on the deal. The deal cannot be announced until the official start of free agency on Wednesday.